Search results

1 – 10 of 15
Article
Publication date: 26 June 2018

Rehan Zahid, Masjuki Hj. Hassan, Abdullah Alabdulkarem, Mahendra Varman, Md. Abul Kalam, Riaz Ahmad Mufti, Nurin Wahidah Mohd Zulkifli, Mubashir Gulzar, Muhammad Usman Bhutta, Mian Ashfaq Ali, Usman Abdullah and Robiah H. Yunus

There is a continuous drive in automotive sector to shift from conventional lubricants to environmental friendly ones without adversely affecting critical tribological performance…

Abstract

Purpose

There is a continuous drive in automotive sector to shift from conventional lubricants to environmental friendly ones without adversely affecting critical tribological performance parameters. Because of their favorable tribological properties, chemically modified vegetable oils such as palm trimethylolpropane ester (TMP) are one of the potential candidates for the said role. To prove the suitability of TMP for applications involving boundary-lubrication regime such as cam/tappet interface of direct acting valve train system, a logical step forward is to investigate their compatibility with conventional lubricant additives.

Design/methodology/approach

In this study, extreme pressure and tribological characteristics of TMP, formulated with glycerol mono-oleate (GMO), molybdenum dithiocarbamate (MoDTC) and zinc dialkyldithiophosphate (ZDDP), has been investigated using four-ball wear tester and valve train test rig. For comparison, additive-free and formulated versions of polyalphaolefin (PAO) were used as reference. Moreover, various surface characterization techniques were deployed to investigate mechanisms responsible for a particular tribological behavior.

Findings

In additive-free form, TMP demonstrated better extreme pressure characteristics compared to PAO and lubricant additives which are actually optimized for conventional base-oils such as PAO, are also proved to be compatible with TMP to some extent, especially ZDDP. During cylinder head tests, additive-free TMP proved to be more effective compared to PAO in reducing friction of cam/tappet interface, but opposite behavior was seen when formulated lubricants were used. Therefore, there is a need to synthesize specialized friction modifiers, anti-wear and extreme pressure additives for TMP before using it as engine lubricant base-oil.

Originality/value

In this study, additive-free and formulated versions of bio-lubricant are tested for cam/tappet interface of direct acting valve train system of commercial passenger car diesel engine for the very test time. Another important aspect of this research was comparison of important tribological performance parameters (friction torque, wear, rotational speed of tappet) of TMP-based lubricants with conventional lubricant base oil, that is, PAO and its formulated version.

Details

Industrial Lubrication and Tribology, vol. 70 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 8 June 2015

Riaz Ahmad Mufti, Rehan Zahid, Farrukh Qureshi and Jawad Aslam

The purpose of this paper is to understand the effect of engine operating conditions and lubricant friction modifier on direct acting tappet rotation. In this research work, novel…

Abstract

Purpose

The purpose of this paper is to understand the effect of engine operating conditions and lubricant friction modifier on direct acting tappet rotation. In this research work, novel method of measuring engine tappet rotation speed has been developed. The technique is so novel. It allows the measurement on real production engine with no modification to the engine tappet bore. Also, In this paper, the effect of engine operating conditions and the effectiveness of friction modifier on tappet rotation is reported.

Design/methodology/approach

For the very first time, for the purpose of measuring follower rotation in a real production engine, a 4 × 6 mm2 electronic chip called Gradiometer is mounted outside the tappet housing, allowing the monitoring of tappet rotation speed without the need to machine a hole in the tappet bore. This novel technique is adopted on Mercedes Benz OM464 engine to study the effect of engine conditions and lubricant chemistry on tappet performance.

Findings

The main outcome of this research work is the development of novel method of measuring tappet rotation. Also, during the experiments, it was revealed that although friction modifiers help in reducing friction at the cam/tappet interface, they can also adversely affect the tappet rotation speed.

Originality/value

The novel technique developed in the research work is one of the most cost effective and simple to use. Researches can adopt the technique to study the tribological performance of direct acting tappet on real production engine. Researches acknowledge the effectiveness of friction modifiers in valve train but its effect on rotation which plays a key role in the component durability has not been the focus of most of the researches mainly due to lack of effective techniques.

Details

Industrial Lubrication and Tribology, vol. 67 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 July 1977

DESPITE assurances from the Union most concerned that “every endeavour will be made to keep Montague Burton workers in employment” it seems inevitable that the massive…

Abstract

DESPITE assurances from the Union most concerned that “every endeavour will be made to keep Montague Burton workers in employment” it seems inevitable that the massive redundancies announced a month ago will take place. Nor does it seems possible that these unfortunate people will readily find employment elsewhere — certainly not in the towns where they are living and working now. In every sense, it will mean a major upheaval for most of them.

Details

Work Study, vol. 26 no. 7
Type: Research Article
ISSN: 0043-8022

Article
Publication date: 1 December 1981

HARDLY had the dispute at BL ended and the men had gone back to work amidst universal rejoicing (apart from the more militant of the shop stewards) than several hundred of them…

Abstract

HARDLY had the dispute at BL ended and the men had gone back to work amidst universal rejoicing (apart from the more militant of the shop stewards) than several hundred of them had to be sent back home, rightly on full pay, because of a plague of fleas that had invaded the factory. Talk about scratching for a living…!

Details

Work Study, vol. 30 no. 12
Type: Research Article
ISSN: 0043-8022

Article
Publication date: 1 February 1983

G.D. EDWARDS

The function of an internal combustion engine valve spring is to provide sufficient force throughout the engine cycle to maintain the tappet in contact with the cam at all speeds…

Abstract

The function of an internal combustion engine valve spring is to provide sufficient force throughout the engine cycle to maintain the tappet in contact with the cam at all speeds within the engine speed range. However, it must not exert such force that will produce unacceptable contact stresses between tappet and cam. The performance requirements of a valve spring are that it must not fail by fracture or, by load relaxation, lose so much of its controlling force that it fails to maintain control between tappet and cam.

Details

Industrial Lubrication and Tribology, vol. 35 no. 2
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 25 November 2019

Jian Zhang and Tingting Luo

The purpose of this paper is to study the variation of cavitation scale with pressure and flow in poppet throttle valve, to obtain the cavitation scale under pressure and flow…

Abstract

Purpose

The purpose of this paper is to study the variation of cavitation scale with pressure and flow in poppet throttle valve, to obtain the cavitation scale under pressure and flow conditions and to provide experimental support for the research of suppressing throttle valve cavitation and cavitation theory.

Design/methodology/approach

A hydraulic cavitation platform was set up, a valve was manufactured with highly transparent PMMA material and a high-speed camera was used to observe the change in cavitation scale.

Findings

Through experiments, it is found that the pressure difference between inlet and outlet of throttle valve affects the cavitation scale, and the more the pressure difference is, the easier the cavitation will be formed. Under the condition of small pressure difference, the cavitation is not obvious and reducing the pressure difference can effectively suppress the cavitation; the flow rate also affects the cavitation scale, the smaller the flow rate, the more difficult the cavitation will be formed and the lower the flow rate, the more the cavitation will be suppressed.

Research limitations/implications

Because of the magnification factor of the high-speed camera lens, the morphology of smaller bubbles cannot be observed in this study, and the experimental conditions need to be improved in the follow-up study.

Originality/value

This study can provide experimental support for the study of throttle valve cavitation suppression methods and cavitation theory.

Details

Industrial Lubrication and Tribology, vol. 72 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 October 1941

Raymond W. Young

THE Mercedes‐Benz Model DB‐601A aero‐engine is a development of the Daimler‐Benz Aktiengesellschaft of Stuttgart, Germany, a firm which lias been engaged in the manufacture of…

Abstract

THE Mercedes‐Benz Model DB‐601A aero‐engine is a development of the Daimler‐Benz Aktiengesellschaft of Stuttgart, Germany, a firm which lias been engaged in the manufacture of automotive and aero‐engines for over fifty years. During the first World War the Daimler Motorcn Gesellschaft of Stuttgart produced the famous Mercedes aero‐engines iii three 6‐cylindcr types with ratings of 160 horse‐power, 180 horse‐power, and 260 horse‐power. Equally renowned were the 160 horse‐power and 230 horse‐power 6‐cylindcr aero‐engines built by Benz and Company in Mannheim. After the war, and as a result of the economic and financial crisis which brought almost complete stagnation to the automotive industry in Germany during the early twenties, these two companies were practically forced to combine their activities in order to survive. Accordingly in 1926 a merger was consummated between the Daimler and Benz organizations. Thus came into being the firm of Daimler‐Benz A.G. and their product, the Mercedes‐Benz line of automotive vehicles and aircraft power plants.

Details

Aircraft Engineering and Aerospace Technology, vol. 13 no. 10
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 August 1980

ONLY two months ago (June issue) this journal advocated the more general utilisation of robots in manufacturing industry coupled with a reduction in working hours so that all…

Abstract

ONLY two months ago (June issue) this journal advocated the more general utilisation of robots in manufacturing industry coupled with a reduction in working hours so that all possible should have a share in what work remains available for humans to do.

Details

Work Study, vol. 29 no. 8
Type: Research Article
ISSN: 0043-8022

Article
Publication date: 13 March 2017

Waseem Arshad, Muhammad Adnan Hanif, Muhammad Usman Bhutta, Riaz Ahmad Mufti, Samiur Rahman Shah, Muhammad Usman Abdullah and Muhammad Huzaifa Najeeb

This paper aims to present a technique that has been developed to study the wear in the camshaft and tappet. The engine manufacturers use the most suitable materials, lubrication…

Abstract

Purpose

This paper aims to present a technique that has been developed to study the wear in the camshaft and tappet. The engine manufacturers use the most suitable materials, lubrication additives and surface coatings to minimize friction in all the components of the engine. Reduced friction results in less wear of critical engine components. The researchers are constantly trying to find an improved lubrication formula which reduces the wear and friction coefficient at a considerably low price. In this regard, the cam follower interface is of much importance because most of the wear occurs in this interface.

Design/methodology/approach

The tappets and the cam lobes are analyzed to determine wear. A two-dimensional optical surface profilometer is used to measure the tappet wear, and a high-resolution linear variable differential transformer is used for the measurement of cam lobes. Tests are conducted on Mercedes Benz engine OM 646 under constant camshaft speed, constant inlet lubricant temperature and constant lubricant pressure to study the oil rheology on cam tappet wear.

Findings

The results show that the wear occurs on the cam tappet interface, which is almost a linear phenomenon, and it increases with use.

Originality/value

Customized jigs were made to measure wear of camshaft and tappet.

Details

Industrial Lubrication and Tribology, vol. 69 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 8 February 2016

Ahmad Firdaus Shamsul Baharin, Mariyam Jameelah Ghazali and Juyana A Wahab

– The purpose of this paper is to make people aware of the increase usage of laser system in surface texturing process.

1558

Abstract

Purpose

The purpose of this paper is to make people aware of the increase usage of laser system in surface texturing process.

Design/methodology/approach

As it is a brief review paper, no particular method was used.

Findings

It has been found that most of the surface texturing methods used mas laser beam machining using Nd:YAG laser. It shows that the realization of the textured surface helps to reduce friction and wear which can increase the life span of a material.

Research limitations/implications

Most of the texturing is done on the substrates directly, and few research were conducted on coated surface of the material, which coating is also known as an excellent method to improve tribological properties.

Originality/value

The paper shows details on the recent development of surface texturing and its contribution to friction and wear reduction.

Details

Industrial Lubrication and Tribology, vol. 68 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

1 – 10 of 15